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Power Build Hardware Technology

Advance In Super/Ultra Capacitor Tech: High Voltage and High Capacity 147

fyngyrz writes: Ultracaps offer significantly faster charge and discharge rates as well as considerably longer life than batteries. Where they have uniformly fallen short is in the amount of energy they can store as compared to a battery, and also the engineering backflips required to get higher voltages (which is the key to higher energy storage because the energy stored in a cap scales with the square of the cap's voltage, whereas doubling the cap's actual capacitance only doubles the energy, or in other words, the energy increase is linear.) This new development addresses these shortcomings all at once: considerably higher voltage, smaller size, higher capacitance, and to top it off, utilizes less corrosive internals. The best news of all: This new technology looks to be easy, even trivial, to manufacture, and uses inexpensive materials — and that is something neither batteries or previous types of ultracaps have been able to claim. After the debacle of EEStor's claims and failure to meet them for so long, and the somewhat related very slow advance of other ultracap technology, it's difficult not to be cynical. But if you read TFA (yes, I know, but perhaps you'll do it anyway) you may decide some optimism might actually be called for.
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Advance In Super/Ultra Capacitor Tech: High Voltage and High Capacity

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  • by Shadow of Eternity ( 795165 ) on Wednesday September 30, 2015 @07:45AM (#50625903)

    We're getting to a point where the issue isn't just how much energy we can store in how little space, and how readily we can use it, but also how stable that medium is and how gracefully it fails when mishandled. Cellphone batteries are already pretty scary when punctured, imagine something holding several times as much energy.

    • You said it. We want a lot of energy in a hand-held format. But it's dangerous.

      That energy will get hacked for purposes both good and bad, and the bad purposes will include explosions.

      • by sjbe ( 173966 ) on Wednesday September 30, 2015 @08:15AM (#50626033)

        You said it. We want a lot of energy in a hand-held format. But it's dangerous.

        Do you have any comprehension of the amount of energy stored [wikipedia.org] in a tank of gasoline? A lot of energy stored is not in and of itself dangerous. What matters is the means by which that energy can be released. Your body stores a huge amount of energy but there is no easy way to release that energy rapidly. Diesel has even more energy than gasoline but good luck igniting it. You can drop a lit match on diesel fuel and nothing will happen. Now do batteries and ultracaps have their own unique failure modes? Sure. But it's not hard to demonstrate that the chances of an explosion are pretty minimal.

        That energy will get hacked for purposes both good and bad, and the bad purposes will include explosions.

        Do you see a lot of exploding cars outside of fictional movies? Causing an explosion normally requires a criminal act typically involving external explosives. It's not actually a very easy thing to cause an explosion. (thank goodness) In most cases even if there is a catastrophic failure the car merely burns, it doesn't explode. I actually trust the engineers working on this stuff and I've worked with companies building battery packs for cars and other high energy applications over the years. They are pretty well aware of the possible failure modes and what to do about them. Explosions aren't something they are overly worried about.

        • by RabidReindeer ( 2625839 ) on Wednesday September 30, 2015 @08:36AM (#50626145)

          Do you have any comprehension of the amount of energy stored [wikipedia.org] in a tank of gasoline?

          Do you have any comprehension of the amount of energy stored in a 3-oz bottle of distilled water?. E=mc^2. If I didn't slip a decimal, the blast radius should run to approximately 6 miles.

          • Do you have any comprehension of the amount of energy stored in a 3-oz bottle of distilled water?. E=mc^2. If I didn't slip a decimal, the blast radius should run to approximately 6 miles.

            Exactly my point. The energy density of a substance is almost irrelevant to the discussion. What matters is whether there is a means to release that energy catastrophically. In most cases there is no easy way to do it. We don't see cell phones detonating. We don't see cars exploding. We don't see laptop batteries going ka-boom. Worst case we normally see is a comparatively gentle and slow combustion. Damaging sure but hardly an explosion.

          • by cpotoso ( 606303 )
            E=mc^2, sure, but unless you have a pathway by which you can go from A-->B lowering the mass (yes, you could fuse the H's, then the O to make Ne (and boy, talk about a high energy barrier to achieve that) you cannot release this energy. BTW: you'd only get [m(H2) - m(Ne)]c^2, which is a lot less than you assumed.
          • by rthille ( 8526 )

            From the label on Larry Niven's softweapon:"Warning, do NOT use setting 7 on planets with an atmosphere!"

        • Actually unless the gasoline is mixed with oxygen the potential energy is zero.

        • Gasoline seems "safe" because the fuel needs to mix with atmospheric oxygen and that slows the energy release, especially if it's in a container.

          A capacitor or lithium-ion battery is more akin to a rocket - fuel and oxidizer held in close proximity, or gun powder where they are literally mixed together.

      • RTFA It isn't about making giant capacitors to hold a ton of power. It's about storing power for microelectronics more easily. Replacing car batteries is a problem that can be solved at a later date.

    • by rwa2 ( 4391 ) *

      It doesn't hold more energy, it merely charges instantly.

      Sure, they have to use higher voltages to store that energy. But current kills, not voltage (which you should appreciate if you ever had experienced an electrostatic discharge)

      • by Mr D from 63 ( 3395377 ) on Wednesday September 30, 2015 @08:17AM (#50626041)
        Capacitors discharge rapidly when shorted, that can make them more hazardous than batteries in certain situations.
        • Capacitors discharge rapidly when shorted, that can make them more hazardous than batteries in certain situations.

          Also less forgiving of sloppy loads.

          An ideal storage capacitor would have some sort of valve mechanism where you could store fast, but limit the discharge rate.

          • Re: (Score:2, Informative)

            by Anonymous Coward

            If only somebody invented diodes and fuses

          • by Khyber ( 864651 )

            No, an ideal storage capacitor will simply store and release energy at maximum possible speed, and nothing more. Diodes and resistors act as flow control valves. Can you imagine the insane PITA it would be to find a proper capacitor with the right diode voltage drop and proper resistor built-in for the job you need?

            This is why electronic components (excepting ICs) are individual pieces and not mashed together in the manner in which you describe.

            • That's assuming that a "storage capacitor" and a traditional capacitor are the same thing. I didn't.

              Heck, there are already batteries that are more than just simple batteries. For example, ones with temperature sensors for charge control.

              • by Khyber ( 864651 )

                "That's assuming that a "storage capacitor" and a traditional capacitor are the same thing. I didn't."

                You should, because a capacitor is storage/filtering and nothing else, period. Exactly like a battery, except it has a far, far higher rate of charge and discharge, and can undergo many, many, many magnitudes of order higher charge/discharge cycles versus a battery.

                "Heck, there are already batteries that are more than just simple batteries. For example, ones with temperature sensors for charge control."

                That

      • by msauve ( 701917 )
        "But current kills, not voltage"

        That's a vast oversimplification. For the same resistance, more voltage results in more current.

        Static discharge is only safe because there's very little energy involved - it lasts a very short time and there's not a lot of stored energy behind it, but there's still a lot of current flowing. Take an old TV with a CRT, turn it on, then unplug it. Now try to remove the anode connection to the CRT by hand (not to be tried by those who value their health). The voltage is sim
        • If only there were a measurement for how powerful electricity really is.....( hint hint...its called Watts ) I remember the good ol' days of disposable cameras...taking a single AA battery to charge a 150V capacitor that was meant to power the flash. Instead, it powered my shock box...pretty good kick for being powered by a AA battery.
          • by msauve ( 701917 )
            If only one could look at a wire and easily say "if I touch that, x watts of power will go into me." By far, the most common situation is that you have a good idea of the voltage, and the conductivity of humans is consistent enough to make that a reasonable measure of the potential threat.
          • 1.5 volts does not make for much of a kick...

        • by rwa2 ( 4391 ) *

          True, but Mr. +5 Insightful fearmonger said these devices would hold "several times as much energy" as cellphone batteries, when TFS just says they're increasing energy density by increasing voltage (and probably modestly at that). These graphene "supercapacitors" at best have still only have about 1/10th the energy density of Li-ion batteries that are melting down when shorted. (~15Wh/kg vs. 100-265Wh/kg) https://en.wikipedia.org/wiki/... [wikipedia.org]

          Sure, if you have a heart condition or something, a jolt of volta

      • by Alioth ( 221270 )

        It's not that simple. A 12 volt lead acid battery won't give you a shock, for instance, even though it's capable of delivering hundreds of amps and stores a lot of energy. Your skin resistance is highly non linear. At low voltages (for example, the voltage your multimeter puts out when measuring a resistance), the resistance from one hand to the other holding the probes with dry skin is a few megohms. But as the voltage rises, there is a point where the resistance dramatically falls and much higher currents

    • Cellphone batteries are already pretty scary when punctured, imagine something holding several times as much energy.

      One of the problems with capacitors charging rapidly is that they can also discharge very rapidly too so any failure would not be graceful. However I'm not sure there is much reason to be optimistic yet for these devices. The article mentions that the way they get high voltages is by connecting the capacitors together. This means they connect them in series which will significantly reduce the actual capacitance since capacitors in series add like resistors in parallel.

      • One of the problems with capacitors charging rapidly is that they can also discharge very rapidly too so any failure would not be graceful.

        That's one of those ideas that sounds right but isn't necessarily actually true. Yes there are ways to rapidly discharge a cap but it doesn't follow that those are failure modes that would be likely. We use capacitors all over the place and most of the failures of them are demonstrably not from catastrophic discharge.

        • We use capacitors all over the place and most of the failures of them are demonstrably not from catastrophic discharge.

          Large capacitors which store significant amounts of energy or the tiny ones in circuits? Particle physics bubble chamber experiments in the 1960/70s used to have magnets which were pulsed by capacitor when the beam hit them. The stories I've heard older colleagues tell about accidents involving the massive capacitor banks suggest that sudden, catastrophic failures can and do occur. With a small capacitors you get a puff of smoke, with massive capacitor banks you get people blown across rooms and seriously

    • by sjbe ( 173966 ) on Wednesday September 30, 2015 @08:24AM (#50626083)

      Cellphone batteries are already pretty scary when punctured, imagine something holding several times as much energy.

      You ARE something that holds several times as much energy. The energy density of animal fat is roughly the same as that of gasoline and both are FAR higher than the energy density of a lithium-ion battery. Whether something is scary has very little to do with the amount of energy it holds. It is the rate and circumstances in which it can be released that matters.

      That said, if something hits me hard enough to puncture my cell phone battery while I'm carrying my phone, the battery combustion is probably the least of my concerns. I'm likely much more concerned with whatever just speared or shot me.

      • by serviscope_minor ( 664417 ) on Wednesday September 30, 2015 @09:09AM (#50626403) Journal

        That said, if something hits me hard enough to puncture my cell phone battery while I'm carrying my phone, the battery combustion is probably the least of my concerns. I'm likely much more concerned with whatever just speared or shot me.

        Really? Think about it: it would really suck if you just got shot and couldn't immediately tweet about it.

        just got shot lol #ouch #deadsoon

      • by CODiNE ( 27417 )

        How about a smartphone that runs off the users own body fat! Just need to figure out how to access the fat... Maybe a belly button attachment.

        Excuse me while I run to the patent office.

    • by AmiMoJo ( 196126 )

      The amount of energy that supercapacitors hold is actually relatively small, compared to batteries. One common use is to support a battery, so for example you might have a modem that can pull 1.5A powered by a lithium cell. Pulling 1.5A for 10ms is much worse than pulling 0.5A for 30mS, in terms of battery life. That's just the way the chemistry works. So you put in a supercap that can deliver the high current and then more slowly recharge from the battery between pulses.

      So in most cases you will probably b

    • by durrr ( 1316311 )

      You will never see it happening.

      Along with the rest of the city block you're in.

    • Oh I`m pretty sure you wouldn`t want to be near any sort of metal penetrated high voltage super capacitor. I mean high voltage, low ESR, high energy density, short circuit. What could possibly go wrong.

      On the other hand. With so much energy and power density, there is so much that could go right!

    • If you want to see an interesting problem, do the basic physics of a capacitor:
      1. Determine #electrons needed to supply 50A for half an hour
      2. Separate those electrons on two plates separated by fractions of a mm (you know, like a capacitor)
      3. Calculate the force between those plates

      Seriously, it's an informative exercise and these are problems straight out of my high school physics book. From memory, if you have 2 pennies with a 1% charge imbalance between them, the electrical repulsive force is enough

      • You, and all of the other people making comments like this, are completely missing the point. There's enough energy in a a water cooler to level texas, but when a water cooler is punctured it just leaks onto the carpet. When a cellphone battery is punctured it's far more enthusiastic.

      • You've just stated the physics of why capacitors can't beat chemical storage (batteries) in real life. As you say this is basic physics, and has been the primary factor limiting the appeal of supercapacitors in real world applications.

    • It is not the available electrical energy stored in the battery that contributes to their potential for catastrophic failure it is just that the battery materials also makes a good fuel for a lithium oxygen fire. This is not the case with a super capacitor that has such good conductive properties. You could do a lot of harm with them by discharging them rapidly through the wrong substance but that requires adding another material or substance to the equation.
    • Interesting note on this point - The Tesla battery has a special "intumescent" material coating the (~7000) battery cells comprising the car battery pack that responds to overheating by expanding and isolating the affected cells. So it essentially has a built in firewall between each of the thousands of component cells that tries to block off overheating or damaged ones from the rest of the pack. It's kind of like having 7000 tiny gas tanks inside the gas tank that each offer some protection against ruptu

  • Moore's law (Score:4, Insightful)

    by fisted ( 2295862 ) on Wednesday September 30, 2015 @07:50AM (#50625927)

    Capacitors. [...] If they finally obeyed Moore’s Law by squeezing themselves down to the microscale

    They never disobeyed Moore's law since Moore's law is about transistor density..

    • I'm still trying to figure out why my money isn't obeying Moore's law.
    • And the term "Moore's law" has always been a problem in itself. It's based on what was seen so far at its creation but it's not a law. But "Moore's average" wasn't catchy, so...
      • by fisted ( 2295862 )

        We're calling a lot of not-quite-laws laws. Betteridge's comes to mind, or Godwin's.

      • by Anonymous Coward

        It's use of the term law as in Newton's Law of Universal Gravitation. I.e. it's an observation.

  • by Anonymous Coward on Wednesday September 30, 2015 @07:59AM (#50625953)

    What's not to like?

    • by rwa2 ( 4391 ) *

      Considering they use Lightscribe on optical media to manufacture it, I'm already looking forwards to some epic DVD-in-microwave videos to come out of this

      https://youtu.be/Fgm0FRN0KbU [youtu.be]

      • by Kythe ( 4779 )
        In all seriousness, there are Youtube videos of hobbyists using this technique to make graphene.
      • It's too bad Lightscribe never became more popular, it was a pretty neat idea. Not as neat as digital watches, but still.
        • The idea of having a cheap consumer device that can so easily etch any bitmap with such fine detail intrigues me. I wonder what else you could etch. If there was a coating for circuit boards that these lasers could etch that would be really cool. Pop a board in your CD burner amd minutes later have a perfectly etched board.

          • by fnj ( 64210 )

            The idea of having a cheap consumer device that can so easily etch any bitmap with such fine detail intrigues me.

            LightScribe doesn't "etch" anything. Using infrared light it reacts with a photoreactive dye. It's the same principle as recording to CDR. You don't "burn" anything when you record a CDR. You just modify a photoreactive dye.

          • There is existing tech that allows light to affect a photosensitive layer on a copper clad board. Do that, wash off the unexposed areas, then submerge the board in chemical etchant. Wait, rinse, dry, and you have a single layer PCB.
    • We're going to need bigger magic blue smoke refilling kits. [sparkfun.com]
  • The DVD-burner graphene etching technique to produce supercaps is several years old -- but it looks like they're continuing to work on it. Good to see the technique hasn't been abandoned.
  • Why can't we use these things in cars? Imagine being able to recharge your car faster than you could fill it up with gas. The station itself could then recharge their built-in ultra capacitors. Even if it takes X seconds to charge a car and five to ten times longer to charge the station back for that amount, it would be impressive. No more "out of gas", no more having huge-ass semi-trucks filled with thousands of litres of gas driving around. Stations could add solar panels for some additional "free" electr
    • Why can't we use these things in cars?

      We already do [roadandtrack.com] use them in cars.

      Imagine being able to recharge your car faster than you could fill it up with gas.

      Not quite that simple. There is a serious heat issue to deal with when you are transferring that much electric power over wires even if the power is available. Filling up something like a Tesla safely in less than 3 minutes is not as easy as it sounds. You can't just pump more juice over the same wires. You start getting into needing superconductors to handle the juice unless you have wires the thickness of your arm.

      Stations could add solar panels for some additional "free" electricity, etc.

      That would be a LOT of solar panels. I'm not sure you ap

      • by Lennie ( 16154 )

        Long term, if solar keeps improving the way it does I would expect cars just have their own panels:
        http://www.greenoptimistic.com... [greenoptimistic.com]

        But it's still a long way away.

    • "Why can't we use these things in cars?"

      The problem is leakage. Current-generation supercaps do not hold a charge long enough to be usable as batteries.

    • by Alioth ( 221270 )

      The charging cables would have to be enormous, though, to fill (say) to a 400 mile range in less than 3 minutes. The currents and voltages required would be absurdly high. Let's say we have a 180kWh battery/capacitor we want to fill in 3 minutes (0.05 hours). The power coupling would be running to the car at 3.6 megawatts during the charge cycle. With a 11kV coupling you'd need a current of almost 330 amps, so big, thick and heavy conductors. Even if the charger was 99% efficient, you'd need to dissipate 36

      • If you actually look at it in a vacuum, instead of as the evolution that got us here, our current gas-station infrastructure is also ridiculous. Inch thick tubes with no safeties pumping volatile fuel anywhere someone wants, that has to be trucked in on a regular basis from refineries often located in different countries than the original oil is produced in, with highly polluting leakage possible at every stage of the game? Ridiculous. And yet we're so used to it we don't even blink. Most of the refuelin

    • China experimented with supercap busses. They charge up off pantograph at the bus stop. The range is awful, but you don't need much range - just enough to make it to the next stop, and the next charge.

  • Higher voltages (Score:5, Informative)

    by overshoot ( 39700 ) on Wednesday September 30, 2015 @08:30AM (#50626113)

    Well, yes, the amount of energy stored goes up as the square of voltage for a given capacitance. However, for a given dielectric getting twice the voltage requires twice the thickness and cuts the charge in half -- so the energy per unit volume is unchanged.

    Which shouldn't be surprising since the energy is stored in the dielectric by (e.g.) straining the molecular structure of the material.

    The biggest reason for going to higher voltages is to reduce the interconnects, which get enormous at low voltages and high currents. (Cross-sectional area goes up inversely with the square of voltage for any acceptable IR loss, which is why long-distance power lines run at scary voltages.)

    • Energy storage is proportional to voltage squared at constant capicatance? Really??? So if I connect two (super)capacitors in series, thereby doubling the voltage limit, I have somehow squared the energy storage! I don't think so!!!

      Power goes up with voltage squared in resistive circuits, but that's a different issue. In this case, you'd get that power for a shorter time.

      • Really??? So if I connect two (super)capacitors in series, thereby doubling the voltage limit, I have somehow squared the energy storage!

        You've also halved the capacitance and doubled the volume. So: twice the voltage (4x), half the capacitance, (0.5x), and twice the volume (0.5x). Looks like your energy density didn't materially change.

      • Two capacitors in series have half the capacitance. If you combine two like that you get exactly what you'd expect: Twice the energy storage of one capacitor.

        You can connect them in parallel. The maths works out he same: Twice the storage.

    • It also makes the electronics a lot easier. A power supply capable of operating over an input range of 10-30 volts is a lot easier to make than one that operates over 1-5 volts.

  • by PeterM from Berkeley ( 15510 ) <petermardahl@ y a h o o.com> on Wednesday September 30, 2015 @08:42AM (#50626187) Journal

    Energy stored is C * V * V / 2. Telling us C without V is sort of like measuring the capacity of a gas tank by giving you the length, but leaving out the depth and width.

    They report capacitances in the 1000 millifarads for a "centimeter scale" device.

    If the maximum voltage is 1V, then we have an unimpressive energy storage of 0.5 J in their "centimeter scale" device.

    AAA batteries can store about 5000 J, by contrast. To match that, these would need to be charged to 100V.

    Without the V number this article is disappointingly uninformative.

    --PM

    • by Anonymous Coward

      The "centimetre scale" device is "1/5th of the thickness of a sheet of paper". So a 1cm cube could contain about 500 of them, depending on the thickness of the paper referenced. So in 1cc 250J can be stored.

      A AAA battery is 10.5mm in diameter and 44.5mm long. So 4.5 centimetre scale devices can fit in the same volume, holding about 1,125J. This is the same volume as a AAA battery usually occupies in a device, as the AAA battery is a cylinder, whereas the centimeter device is a cuboid, but the space around t

      • > 1,125J in an AAA battery size is directly comparable with NiMH rechargeable batteries. 5,000J for an AAA battery is the figure for disposable batteries

        This is really off the mark. I have 1100 mAh, 1.2V rechargeable AAA batteries. 1.1 Ah * 1.2 V = 1.32 Wh ~= 4752J. No idea about the disposable batteries.

  • High voltage, compact size, easy to make. I'm sure this will somehow be used in porn first (the 'how' eludes me but there seems to be a Rule 34 about tech) - yet "Everything that can be weaponized, will be weaponized..."

  • by koan ( 80826 )

    As a kid in electronics class out teacher wired up a capacitor incorrectly to demonstrate what would happen if we weren't cautious.
    The resulting explosion was surprisingly powerful.

    I wonder what an ultra cap would do in the same situation

    • by PPH ( 736903 )

      That sounds like (no pun intended) an electrolytic cap reverse polarized. I scanned TFA and didn't see anything about these supercaps being polarized. So charging them backwards should work just as well as forwards.

  • by laughingskeptic ( 1004414 ) on Wednesday September 30, 2015 @10:29AM (#50627247)

    If they had an electrolyte that worked in this application they wouldn't be talking about all the possible choices. They would tell us what worked.

    "For this solid electrolyte, we have plenty of choices. We can use gelled polymer electrolytes, made by swelling a polymer matrix with an electrolyte solution, or we can solidify ionic liquids by adding polymers or silica nanopowder. This nonleaking design, together with a virtually unlimited number of charge and discharge cycles, means that our supermicrocapacitors will likely outlast all other electronic devices on the chip. Such long life will be particularly useful whenever it is inconvenient or dangerous to open things up to replace a power source, as in pacemakers, defibrillators, and other medical implants."

    Electrical and magnet fields occur in 3 dimensions, not one. They can talk about the gap between the fingers of their layout, but their effective average gap in 3D is probably closer to PI*center_distance/2 which gives a lesser result for the expected capacitance. Their max voltage with a given electrolyte is limited to the closest edge, but that is not how a physicist would compute expected capacitance.

  • by egor duda ( 36055 ) on Wednesday September 30, 2015 @11:37AM (#50627867)

    From here [sciencedirect.com]

    We employed these hybrid electrodes for building aqueous-based symmetric and asymmetric cells that can deliver energy densities up to 55.3 Wh kg-1, placing them among the best performing hybrid electrochemical capacitors.

    • > placing them among the best performing hybrid electrochemical capacitors.

      Which still sucks by orders of magnitude compared to batteries.

  • The use of supercapacitors as storage devices is severely limited by their discharge curve (compared with batteries) - google it.
  • See subject.

    • by rthille ( 8526 )

      Derived from RTFM (Read the fucking manual), an exhortation from experienced computer users to newbies when they asked dumb questions. Since no one on slashdot reads TFA, there was enough similarity for it to be adopted.

  • We've all been anesthetized by the constant daily 'AMAZING NEW BATTERY TECH AROUND THE CORNER!' articles over the past X years.. but this one doesn't sound like they are doing the 'if only we could do X' to make it work commercially.. these guys even suggest you could start right now with a room full of DVD burners. they even state there's a startup company already started on making the stuff commercially for the market. I for one will remain a bit optimistic on this one...

    I don't think we'll see this tec

  • 1 Capacitors hold charge between two plates separated by the electrolyte, and typically excess electrons accumulate on one conducting plate as a cloud. Once you reach a certain voltage, the insulation fails = punch-through. If self healing, the voltage will fall and the arc will stop before the charge is gone. If not, most of the charge will dissipate.

    2 Capacitors are the mechanical analog of the spring, more force = more spring stretches, in the same way as you charge a capacitor the voltage increases

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